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62 lines
2.2 KiB
C++
62 lines
2.2 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// test unsigned long to_ulong() const;
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#include <bitset>
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#include <algorithm>
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#include <type_traits>
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#include <limits>
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#include <climits>
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#include <cassert>
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template <std::size_t N>
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void test_to_ulong()
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{
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const std::size_t M = sizeof(unsigned long) * CHAR_BIT < N ? sizeof(unsigned long) * CHAR_BIT : N;
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const bool is_M_zero = std::integral_constant<bool, M == 0>::value; // avoid compiler warnings
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const std::size_t X = is_M_zero ? sizeof(unsigned long) * CHAR_BIT - 1 : sizeof(unsigned long) * CHAR_BIT - M;
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const std::size_t max = is_M_zero ? 0 : std::size_t(std::numeric_limits<unsigned long>::max()) >> X;
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std::size_t tests[] = {0,
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std::min<std::size_t>(1, max),
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std::min<std::size_t>(2, max),
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std::min<std::size_t>(3, max),
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std::min(max, max-3),
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std::min(max, max-2),
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std::min(max, max-1),
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max};
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for (std::size_t i = 0; i < sizeof(tests)/sizeof(tests[0]); ++i)
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{
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std::size_t j = tests[i];
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std::bitset<N> v(j);
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assert(j == v.to_ulong());
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}
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{ // test values bigger than can fit into the bitset
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const unsigned long val = 0x5AFFFFA5UL;
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const bool canFit = N < sizeof(unsigned long) * CHAR_BIT;
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const unsigned long mask = canFit ? (1UL << (canFit ? N : 0)) - 1 : (unsigned long)(-1); // avoid compiler warnings
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std::bitset<N> v(val);
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assert(v.to_ulong() == (val & mask)); // we shouldn't return bit patterns from outside the limits of the bitset.
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}
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}
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int main()
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{
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test_to_ulong<0>();
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test_to_ulong<1>();
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test_to_ulong<31>();
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test_to_ulong<32>();
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test_to_ulong<33>();
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test_to_ulong<63>();
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test_to_ulong<64>();
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test_to_ulong<65>();
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test_to_ulong<1000>();
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}
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